Controlling water migration and transformation in foods

Wageningen Food & Biobased Research helps food manufacturers to control water migration and transformation, extending freshness, tastiness and shelf life.

Controlling the water inside food products is key to extending freshness, tastiness and shelf life. Fresh vegetables and fruit, for example, need to retain as much water as possible in order to remain juicy, whereas the opposite applies to dried fruit and vegetables. In fresh bread, keeping water migration to the minimum ensures a crispy crust and a soft crumb. In popcorn or ice cream, a progressive, well-timed water-to-steam cq. water-to-ice transformation results in specific, desired textures. It is a real challenge for food manufacturers to control water behaviour in products, many of which are hydrophilic – making the drying process, for example, very energy intensive. To complicate things further, water behaves differently in different foods. Wageningen Food & Biobased Research gives manufacturers the insights and tools needed to manage water-migration and transformation and so to improve their products and processes.

Water migration

Wageningen Food & Biobased Research is a global leader in the scientific field of water-food interactions. Our broad knowledge and expertise in food technology and food preservation, allied to fundamental and applied research, enables us to address a wide range of food industry issues. Examples include enhancing the juiciness of meat, optimally rehydrating dried vegetables and the most effective methods for salt-reduction. We use in-house developed advanced and reliable thermodynamic models that enable us to predict the water-binding capacity of food products consisting of proteins, polysaccharides and salt. These models also can predict the exact moment that the water - inside products - is converted to steam or ice. Other models developed by our experts allow prediction of the rate of water migration from the inside to the outside of products. We are among a select few research organisations with their own X-Ray Tomography (XRT) imaging facility for detailed investigation of the processes affecting food structures.

Salt reduction in popped snacks

Wageningen Food & Biobased Research has, together with other partners in the Carbohydrate Competence Centre, investigated the effects of reducing the salt content in popped snacks. We learned that to ensure light, airy crispiness we needed to increase the product’s moisture content when reducing the salt level. Optimum expansion was achieved at a moisture level at which product viscosity at boiling temperature exceeded a certain critical value. Boiling temperature and critical viscosity were shown to be dependent on both salt and moisture content.